PRK and LASIK are two of the most popular forms of laser vision correction and each has transformed the vision of countless patients. So, how do you know how to choose between them? Although the basic premise of both treatments is the same, the techniques do vary, and it is this and the associated effects of the different techniques that set them apart from one another. To help you to decide which is right for you, here’s what you need to know about both of these laser vision correction treatments.
PRK stands for photo-refractive keratectomy and it surprises many people to learn that the PRK technique was actually developed before LASIK and is the oldest form of laser vision correction.
LASIK stands for laser-assisted in-situ keratomileusis. This technique was developed from PRK and has one primary difference. However, despite coming later, it is better known than PRK laser vision correction.
As you probably know, laser vision correction works by reshaping the cornea so that light is refracted correctly through the eye and onto the retina, which sends the signal to our brain to tell us what we can see. The exact way in which your cornea will be reshaped will depend on your individual requirements, but some will need to be made steeper while others will need to be flatter in order to refract the light properly.
Nevertheless, the procedure for both PRK and LASIK is essentially the same except for one element – how the cornea is manipulated for the reshaping process. In PRK the laser is applied directly to the surface of the cornea causing a temporary defect in the epithelium, (the most superficial layer). This epithelium subsequently takes 4-7 days to heal. LASIK, however, bypasses the sensitive epithelium to make a flap beneath the epithelium into the inert stroma of the cornea using a micro keratome or femtosecond laser to make the flap. The laser correction is applied then the flap covers the treated area acting like a natural band-aid, providing quicker healing and less discomfort.
There are a number of advantages to choosing PRK for your laser vision correction surgery.
People with thin corneas can be good candidates for PRK. Some patients have a cornea that is particularly thin. This can occur as a result of previous laser vision correction surgery, or it can be genetic. LASIK flap production requires a thicker cornea to be successful and safe over the long term. Fortunately, since PRK doesn’t involve flap creation, patients with thin corneas may still be approved for this procedure.
No risk of flap-related complications. Sometimes, though rare, there can be problems with the flap either at the time of surgery or from incidental trauma postoperatively. Since PRK does not make a flap, these potential issues are reduced.
Reduced risk of post-surgery dryness. Dry eye is a common temporary side effect of LASIK laser eye surgery. However, patients who undergo PRK instead have been found to have a far lower incidence rate of experiencing this condition.
PRK takes a little longer to recover from compared to LASIK. The vision can be blurry and the eye can feel scratchy for 4- 7 days. You will have a contact lens placed on your eye immediately after surgery. This acts as a temporary bandage and stays in place for 4-7 days, while the patient uses eye drops. Once the contact is removed the patient will continue to use eye drops for a longer period of time compared to LASIK. Full vision recovery can be two weeks to several months.
The primary advantage of LASIK over PRK is that you will make a quicker recovery. Your visual acuity may begin to return as quickly as a few hours after your appointment, although it will continue to improve over the coming days. Most patients see very well within 1 week. You should experience minimal discomfort and the scratchy feeling that tends to follow laser vision correction will probably not persist any longer than 48 hours.
While LASIK has a very strong safety profile just like PRK, the biggest risk associated with the procedure is due to the corneal flap element of the technique. Some of the flap-related complications that can arise include:
- Wrinkling or folding of the flap, causing distorted vision
- A foreign body becoming trapped under the flap
- Epithelial ingrowth, which is when cells from the outer portion of the epithelium grow under the flap where they are not supposed to.
- Fortunately all the above are treatable conditions.
In addition to this, patients who undergo LASIK are more likely to experience dry eyes and rarely issues relating to the weakening of the cornea if a large treatment is done. Remember, not all levels of nearsightedness can be treated!
Please remember, studies have shown that in the long term, after 3-6 months, the ultimate visual acuity improvement is equal for both techniques!
There are advantages and disadvantages to both forms of laser eye treatment, but both can permanently transform your vision and enable you to decrease your dependence on glasses or contact lenses. In general, the decision as to PRK or LASIK will be made by your doctor. For more information, or to schedule a consultation to see what is right for you, please contact our office.